<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>display: flex</title>
    <style>
        .flex-container {
            display: flex;
            gap: 10px;
            border: 1px solid #ccc;
            padding: 10px;
        }

        .item {
            background-color: lightseagreen;
            padding: 100px;
        }
    </style>
</head>
<body>

<div class="flex-container">
    <div class="item">项目1</div>
    <div class="item">项目2</div>
    <div class="item">项目3</div>
</div>

</body>
</html>